<html>
    <head>
        <title>Test</title>
        <style>
          @import url(overlay.css);
        </style>
        <script type="text/tiscript">
       
        event click $(#start) {
          self.postEvent("waiting","Waiting for DB to execute"); // start waiting with the message
          self.timer(5s, function() {
             self.postEvent("waiting",false); // done waiting
          });
        }

        </script>
    </head>
    <body>

      <button#start>Start waiting for 5 seconds</button>

    </body>
    <overlay id="waiting" />
</html>